1. Field of the Invention
The present invention relates to a continuous conveying apparatus in which going and returning ways are unified three-dimensionally, so as to contribute to saving of materials, simplification of structure, reduction of installation expenses and reduction of energy consumption in an escalator, a moving walk, a moving slope, and a conveyer for articles.
2. Description of the Related Art
In known escalators, moving walks and the like of an unified going/returning way type, tread faces move two-dimensionally in a turning around section. Therefore, those escalators and the like can not be provided with driving elements (roller chains, link series or racks) on both sides of steps as in ordinary escalators and the like, and they are allowed to have a continuous driving element only at one position in an inner or central area of the steps. This makes the tread faces unstable during traveling and complicates the structure of the escalators and the like. Thus, many inventions have been made on this type of escalators and the like, but there is not any invention in practical use.
An object of the present invention is to provide a continuous conveying apparatus of unified going/returning ways type, which has continuous driving elements on both sides of the tread faces in a turning around section.
A three-dimensional structure is necessary for turning around a straight-traveling belt member without stretching the same. Practically, there are a way of revolving tread faces helicoidally by 180xc2x0 to reverse it, and a way of twisting the tread faces by 90xc2x0 to stand it up. First, the way of 180xc2x0 reversing will be described. In FIG. 1a, a belt member 1 traveling straight on a horizontal plane is wound on a horizontal cylinder 30 in contact with the belt member 1 on the lower side thereof with its axis inclined at an angle A to the traveling direction 1a of the belt member 1. The tread faces of the belt member 1 turns by 180xc2x0 to form a helicoid, and then horizontally travels in a direction 1b which is inclined at an angle of 2(90xc2x0xe2x88x92A) with respect to the direction 1a. Then, the belt member 1 is wound onto a horizontal cylinder 40 (having the same diameter as the cylinder 30) in contact with the belt member 1 on the upper side thereof with its axis inclined at an angle B with respect to the direction 1b. The tread faces of the belt member 1 turns by 180xc2x0 to form a helicoid, and then horizontally travels in a direction 1c. In order that the direction 1a and the direction 1c are parallel to each other, the following equation has to be satisfied based on the theorem of parallel lines.
2(90xc2x0xe2x88x92A)+2(90xc2x0xe2x88x92B)=180xc2x0
From this equation, A+B=90xc2x0 is derived. Here, B is an angle formed by the horizontal cylinder 40 and the belt member 1 traveling in a direction 1c parallel to the direction la after the turn. If A=B, A=B=45xc2x0. This case is advantageous in respect of design and manufacture. The description will be hereinafter made on this case. In a case where a train of conveying members traveling on rails is used in place of a belt member, the train of conveying members are guided by helicoidal rails running around the axis 3a of the cylinder 30 and the axis 4a of the cylinder 40 instead of the cylinders 30, 40. Use of round bars or round pipes as rails facilitates the design and manufacture of the apparatus. In the following description, a horizontal plane is replaced by a slope plane in a case of running of the tread faces on a slope.
As shown in a plan view of FIG. 1b and a side view of FIG. 1c, when A=B=45xc2x0, the belt member 1 is guided helicoidally around the axis 3a which is below and parallel to the tread faces and inclined at an angle of 45xc2x0 with respect to the traveling direction 1a toward the opposite traveling way, and a driving force transmitting mechanism operates. The contiguous tread faces are formed on twistable belt member 1. After the tread faces travel in the direction 1b, the belt member 1 moves to the opposite way by a helicoidal revolution around the axis 4a inclined at an angle of 45xc2x0 in the opposite direction of the axis 3a, to complete the turn. With the three-dimensional structure, the belt member 1 can be turned with its driving mechanism maintained. A guide surface of the guide member operates to prevent the belt member from dropping off the course in the folding section. When the driving elements and supporting elements are provided on the back side of the belt member 1, enveloping surface of their movement generally form a helicoid. It is possible to increase the stability of operation by guiding the belt member by a guide face on the basis of a part of the helicoid.
In a case where a belt member is substituted by a train of steps interconnected and driven by roller chains, a left portion driven by a left roller chain and a right portion driven by a right roller chain have to take a twisted positional relationship in the helicoidal revolution. In this case, each step 5 is divided into left and right halves 51, 52, and the left and right halves are connected by a transverse cylindrical shaft 53 so that they can take the twisted positional relationship. Supporting rollers may be brought into contact with a cylindrical guide surface at one point and with an inclined posture, and guide rails may be formed of cylindrical tubes so as to simplify the guide surface.
In the case of twisting the tread faces by 90xc2x0 to stand up, as shown in a side view of FIG. 13a and a plan view of FIG. 13b, a belt member 1 is helicoidally turned or twisted by 90xc2x0 about an axis 2a which coincides with a central line of its traveling way in a sloping traveling section Exe2x86x92F, so that the tread faces stand up. After passing a buffer section FG, the belt member 1 is driven and guided circularly by a sprocket S1 and a circular guide S2 around an axis 2b in a circular turning section GGxe2x80x2, and proceeds to a re-tuning section Fxe2x80x2Exe2x80x2 through a buffer section Gxe2x80x2Fxe2x80x2. In the re-turning section Fxe2x80x2Exe2x80x2, the belt member 1 is helicoidally turned or twisted with its tread faces laid, by 90xc2x0 about an axis 2c which is parallel to the axis 2a, to travel on the opposite way.